Anthropogenic regulation of the phosphorus balance in the Thau catchment–coastal lagoon system (Mediterraean Sea, France) over 24 years

In the Thau lagoon, despite there being no phosphate limitation policy, the annual mean phosphate concentrations decreased by 90% between 1971 and 1994. The present study indicates a relationship between the decrease of phosphate concentrations and changes in urban, industrial and agricultural activities within the catchment generating phosphorus (P) inputs; and shellfish farming leading to phosphorus storage and export. The relationship (tonnes of P) is: P–PO 4 3− in the lagoon waters=1.0124 anthropogenic phosphorus balance––47.62 ( r 2=0.824, p